Our laboratory will be involved in three major research projects directed towards determining the population dynamics of genetic loci exhibiting meiotic drive, especially in relation to the possibility of using Y-chromosome drive as a means of pest population control. (1) We will attempt to increase the efficiency of pseudo-Y drive exhibited by translocation lines which couple the Y chromosome to the autosomal drive locus SD. Such lines give unisexual male progeny. The fitness of such pseudo-Y drive can be improved by increasing the segregation of Y plus SD from X plus SD plus to reduce the frequency of the wasted zygotic lethals. This can be accomplished in one of two ways: (a) by the insertion of the Y chromosomal pairing and fertility factors into the SD chromosome, or (b) by moving the SD complex out of its second chromosome milieu onto the Y chromosome (enabling us to investigate questions concerning the structure and dosage relationships of the several components of the SD system). (2) We will examine the dynamics of the long-term accumulation of drive suppressors in population cages where Y drive lines are competing with normal flies. Of particular interest is whether suppressors can accumulate fast enough to prevent drive-induced population extinction. This information will be used to generate theoretical population genetic models which more accurately predict the fate of drive systems in natural populations. (3) We will examine natural insect populations with the hope of finding new cases of meiotic drive.